Press-punch.



J. H. GAMBLE. 7

PRESS PUNCH.

APPLICATION FILED JUNE 10, 1908.

7 Patented Jan. 11,1910.

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JAMES H. GAMBLE, OF KENOSI-IA, WISCONSIN, ASSIGNOR TO RICHARD LARINER,OF KENOSI-IA, WISCONSIN.

PRESS-PUNCH.

Specification of Letters Patent.

Patented J an. 11, 1910.

Application filed June 10, 1908., Serial No. 437,780.

To all whom it may concern:

Be it known that I, JAMES H. GAMBLE, a citizen of the United States,residing at Kenosha, in the county of Kenosha and State of Wisconsin,have invented a new and useful Press-Punch, of which the following is aspecification.

This invention relates to press punches and its principal object is toprovide a punch of the character described through the use of which theloss of the material, due to broken punches, will be minimized.

Another object of the invention is to provide a unitary punch forpunching presses, in which buta small proportion of high grade toolsteel shall be used.

A still further object of the invention is to strengthen the generalconstruction of punch presses.

The invention consists in general of a punch built up largely of machinesteel or a lower grade tool steel combined with a punch poirlit ofhighly tempered high. grade tool stee The invention consists further incertain novel details of arrangement and combination of parts,hereinafter fully described, illustrated in the accompanying drawings,and specifically set forth in the claim.

In the accompanying drawings, like characters of reference indicate likeparts in the several views, and; Figure 1 is a view of a punch pressplunger showing the device applied thereto, the same being shown insection. Fig. 2 is a similar view with still other portions in section.

The numeral 10 indicates the plunger head which is provided with theusual threaded end 11. Mounted thereon is a holder 12 threadedinteriorly and of the ordinary form. These parts are those used in theordinary punching machine to hold the punch in position thereon, andform no part of the invention, but are merely illustrative of the mannerof using the same.

The invention itself consists of a sleeve 13 provided with a centrallydisposed longitudinal opening therethrough, this opening having acylindrical portion 14:, and a frusto-conical lower end as indicated at15. Upon the upper end of the sleeve 13 are formed threads 16, and belowthe threaded end is preferably formed a nut 17 usually hexagonal incross section. Below the nut 17 the sleeve is turned or otherwise formedinto a frusto-conical portion 18, the smaller diameter of which is butslightly larger than the smaller diameter of the frusto-conical portion15 of the longitudinal opening through the sleeve. In the formation ofthe sleeve, which is preferably made either of a low grade of toolsteel, or of machine steel, the sleeve is first drilled to the smallerdiameter of the frusto-conical portion. This is then counterbored to thelarger diameter of said frusto-conical portion and a taper reamer isthen inserted and the lower end reamed out to form the frusto-eonicalpor tion. A punch 19, of the usual shape so far as the lower end isconcerned, is constructed of a high grade of well tempered tool steel.This punch may be formed by turning from a bar of steel or may be forgedin a suitable die. The upper end 20 of the punch is frusto-conical tofit the frusto-conical end of the opening in the sleeve. In thisconnection it is to be noted that the lower end of the punch must be ofsuch size that it will pass through the smaller end of the frustoconicalopening 15. This punch is inserted in the sleeve by dropping the same infrom the upper end. In the cylindrical portion of the sleeve opening 14,is held a distance block 21. This distance block is arranged so that itprojects slightly above the upper end of the sleeve as clearly shown inFigs. 1 and 2. A cap 22 provided with a central recess 23 has suitablescrew threads in that recess to engage the threaded portion of thesleeve 13. This cap is further provided with an annular flange 2 1. Alook nut 25 is carried on the threaded portion of the sleeve below thecap and serves to firmly hold the same in position when screwed on thesleeve.

In the operation of assembling the device the lock nut is first screwedon the sleeve from the top and positioned well down toward the lower endof the threaded por tion. The punch point 19 is then dropped through thesleeve, and the distance block 21 positioned above the same. The sleeveis then screwed in the cap 22, and is forced down as far as possible sothat it is brought into intimate contact with the distance block 21,which in turn is forced firmly against the frusto-conical portion 20 ofthe punch point 19. The lock nut is then screwed up against the sleeveand serves to prevent the same working loose at any time. The purpose ofthis is to make a unitary combination in which pressure applied to thecap will be transmitted directly to the point of the punch in. astraight line, and in which no stress, other than that due to screwingthe cap on the sleeve, will be brought on the threads on the sleeve orin the cap. It is also on this account that the end of the distanceblock 21 projects above the end of the sleeve, thus insuring contactbetween the cap and the said distance block. The device as thusassembled is held in the usual manner on the plunger, by the holder 12,this being clearly seen in Fig. 1.

Attention is called to the fact that by reason of the relatively smallamount of high grade tool steel used in the construction of theinvention, the loss through broken punch points is minimized. Anothergreat point of advantage is that in case of a broken punch point, it isnot necessary to reconstruct the entire device but it is simplynecessary to disassemble the parts and insert a new punch point. A stillfurther advantage of a device as constructed in this manner is that thelower end of the sleeve forms a brace and support for the punch point,and may be made as heavy as desired for that purpose. Owing, however, toits peculiar shape it is not necessary to employ a very heavy crosssection for this purpose, the frusto-conical exterior acting as acylindrical buttress t0 the punch at the point of greatest stress.

It is obvious that many changes may be made in the form and proportionsof the device without departing from the material principles thereof. Itis not therefore desired to confine the invention to the exact formherein shown and described, but it is wished to include all such asproperly come within the scope of this invention.

Having thus described the invention what is claimed as new, is

A press punch device comprising an externally threaded sleeve having asmooth cylindrical bore and a frusto-conical bore, communicating at oneend with the cylindrical bore, a punch point having a frustoconicalportion to fit snugly within the frusto-conical bore of the sleeve, adistance block fitting snugly within the cylindrical bore of the sleeveand projecting above the same, an internally threaded cap receiving thethreaded end portion of the sleeve and bearing against the projectingend of the distance block, and a lock nut upon the thread of the sleeveand bearing against the end of the cap.

In testimony that I claim the foregoing as my own, I have hereto aflixedmy signature in the presence of two witnesses.

JAMES H. GAMBLE.

lVitnesses MARTHA SOHUMACHER, AUcUsT H. KLUENDER.

